Blowing device



Aug. 17, 1937. .1. c. CURTIS BLOWING DEVICE Filed Dec. 28, 1956 JOHN C'- C'I/E 77-5 INVENTOR ATTORNEY .the several views, l

atented Aug. 17, 1937 UNITED STATE 2,090,032 BLOWING DEVKGE John C. Curtis,

to The Cleveland Garfield Heights, Ohio,

Rock Drill Company,

assignm- Cieve land, Ohio, a corporation of Ohio Application December Claims.

This invention relates broadly to rock drills, but more particularly to a blowing device for fluid! actuated rock drills of the hammer type.

One object of this invention is to effectively supply pressure fluid to the bottom of the drill hole for removing the cuttings therefrom.

Another object of this invention is to provide a rock drill having a passage for intermittently admitting motive fluid to the drill steel during the normal operation of the drill, with means for automatically closing that passage during the blowing operation.

Another object of this invention is to provide a rock drill blowing device of simple construction, which is strong, durable and efficient.

In the drawing:

Fig. 1 represents a longitudinal sectional view of a rock drill with the parts positioned for normal operation.

Fig. 2 is a view similar to Fig. 1 with the parts positioned for blowing operation.

Referring to the drawing in which like symbols designate corresponding parts throughout represents the main housing formed with a cylindrical chamber H having, reciprocable therein, a hammer piston i2. The upper end of the chamber II is enlarged to accommodate a valve block l3, and valve cap I4, within which is reciprocably mounted a fluid actuated valve l5 controlling ports l6 and l! which lead respectively into the upper and lower end of the chamber ll.

Secured within the lower portion of the chamber l I, there is a spacer I8 formed with a through bore 19 adapted to slidably receive a closely fitted stem 20, which stem forms a part of the piston 12. The lower portion of the stem 29 is provided with splines 2| slidably engaging similar splines 22 formed within the bore 23 of a chuck 24, which chuck is rotatably mounted within a front housing 25. The chuck 24 is also machined to slidably but non-rotatably receive a drill steel 26 which extends into the bore 23. Through the drill steel 26 is provided a bore 2'5.

Located in the chamber H above the valve block 13, there is a rotation mechanism including a ratchet ring 28 associated with a rifle bar 29 through pawls 39. This bar extends into the hammer l2 for operative engagement with a rifle nut 31, through which rotation is trans mitted to the piston, and in turn to the drill steel through the chuck 24.

Secured on top of the housing in, there is a head 32 engaging a plate 33 mounted between the head 32 and the ratchet ring 28. -The head 28, 1936, Serial No. 117,746

32 is machined to rotatably receive a throttle valve 3 4 formed with a central or inlet port 35 having motive fluid admitted therein. Radially disposed through the throttle valve 34 there are ports 35 and 31, the former capable of communication with either a port 38 formed through the plate 33 or a port 39 formed within the head 32, while the latter is capable of communication with a smaller port ll) provided within the head 32. Between the ports 35 and 31, the throttle valve is formed with a groove 4! capable of affording communication. between the port 40 and a vent 2.

The port 39 opens into a groove 43 formed within the plate 33, which groove is in constant communication with the valve through ports it.

The head 32 is formed with a threaded bore 55 disposed coaxially with the chamber H and having secured therein a plug 46. This plug is formed with a fiat bottom bore il having slidably mounted therein a cup-shaped bushing 48 accommodating the head Q9 of a needle 55]. This pin or needle extends through the rifle bar into the hammers stem 28, which is formed with a through bore having three different diameters, one enlarged diameter 5i accommodating the rifle bar 29, an intermediate diameter 52, and a small diameter 53 adapted to slidably receive the pointed end portion of the needle 50. Acting under the head of the needle head i9, there is a compression spring 54 urging the needle into engagement with the bottom of the bushing bore 6?, while this last bore is in constant communication with the port iil through a port 55. Formed within the side wall of the housing It], there is a port 56 having one end opening into the port while the other end opens into an annular groove 5i located around the chuck 24, which groove is in constant communication with the chuck bore 23 through a port 58.

Leading from the chamber H to the atmosphere, there is also provided the usual exhaust passage 5%).

In the normal operation of the drill, the throttle valve 32 is positioned as shown in Fig. 1 mitting motive fluid from the throttle valve bore 33 to the valve i5 through the throttle valve port 35, the head port 39, the groove 43 and the ports ii. From the valve l5, the motive fluid will flow alternatively into the upper and lower portion of the chamber ll through the ports it and ii respectively for efiecting the reciprocation of the piston l2 and the consequential distribution of impacts on the drill steel 26. Durport into the chuck chamber 23, from Where it is free to flow to the bottom of the drilled hole through the drill steel bore 2'! for maintaining the cuttings away from the cutting edge of the drill steel. When the throttle valve is posiport as is in communication With fl Vfilll] i2 tlllOllQh the throttle valve groove 4|, thereby venting the bottom of the plug bore 47 to the atmosphere through the port 55.

When it is desired to clean In this instance motive fluid from the throttle valve port 35 is admitted into the chuck bore 23 via the throttle valve port 36, ports 38 and 56, annular groove 57 and port 53. In the bore 23, the motive fluid will normally exert for eiTectively blowing the cuttings out of the drilled hole.

When it is desired to resume the drilling operation, the throttle valve 34 may again be positioned as shown in Fig. 1. In this instance, the plug bore 41 is again vented to the atmosphere through the ports 55 and 33, valve groove ll and Vent 42, allowing thereby the spring 5 to move the needle 50 into the position shown in Fig. l to enable an intermittent admission of the motive fluid to the bottom of the drilled hole.

any wastage of cleansing fluid, which would otherwise flow through the hammer and escape to the atmosphere via the exhaust port 5 9.

I claim: 7

1. In a fluid actuated rock drill, the combina tion of a cylinder and a hammer piston, a d steel adapted to receive the impacts of the ha mer piston, means including a port through 1 hammer piston intermittently admitting cleai ing fluid to the drill steel, and means for adm ting cleansing flu d to said drill steel indepen ently of said port and for simultaneously closi said port.

2. In a fluid actuated rook drill, the combin hammer piston, a dr steel adapted to receive the impacts or the ban mer piston, means including a port through 53, hammer DlStOh intermittently admitting clean ing fluid to the drill steel, a needle slidable witl in said hammer piston and capable of closir needle for closing said port.

3. In a fluid actuated rock drill, the combina tion of a cylinder, of a hammer cable therein and having a port, a drill stee to receive the impacts of the hammei pressure fluid into said cylinder for actuating said hammer piston and for admitting from said cylinder an intermittent supply of pressure fluid to the bore of said drill steel via said port, and unitary operable means for shutting off the supply or pressure fluid to said cylinder, shutting oiT said port and admitting a constant supply of pressure fluid to the bore of said drill steel.

4. In a fluid actuated rock drill, the combination of a cylinder, of a hammer piston therein, a port through said piston, a drill steel adapted for admitting a constant supply of pressure fluid to the other end of said piston and therefrom to the bore of said drill steel and for automatically closing said port.

5. In a fluid actuated rock drill, the combination of a cylinder, of a hammer piston reciprooable therein, a port through said piston, a needle movable within said port for closing the latter, a drill steel adapted to receive the impacts of said piston and having a bore therethrough, means of said drill steel via said port, and means admitting constant supply of pressure the other end of said piston and therefrom to the bore of said drill steel and for automatically actuating said needle for closing said port.

JOHN C. CURTIS. 

